论文标题
将外壳添加到BPS Skyrme中子星
Adding crust to BPS Skyrme neutron stars
论文作者
论文摘要
Skyrme模型及其概括为核物质的描述提供了概念上吸引人的现场理论基础,并在其与重力耦合后,也为中子恒星耦合。特别是,特定的Skyrme子模型,即所谓的Bogomol'nyi-Prasad-Sommerfield(BPS)Skyrme模型,由于其完美的流体特性,都可以进行精确的现场理论和中子星的均值治疗。然而,纯BPS Skyrme模型描述仅通过结构描述中子星核。在这里,我们考虑了以高重子密度推断BPS Skyrme中子星到较低密度有效的描述的不同可能性。在确切的现场理论情况下,可以使用对中子星形外壳的简单有效描述,因为确切的BPS Skyrme中子星溶液正式扩展到足够低的密度。另一方面,在平均场情况下,BPS Skyrme中子星溶液始终保持在核饱和密度之上,因此必须将其连接到已经用于外核的不同状态的不同核物理方程。我们在两种情况下都研究了所得的中子星,从而促进了从其他方法获得的天星和中子星之间的更完整的比较以及观察结果。
The Skyrme model and its generalisations provide a conceptually appealing field-theory basis for the description of nuclear matter and, after its coupling to gravity, also of neutron stars. In particular, a specific Skyrme submodel, the so-called Bogomol'nyi-Prasad-Sommerfield (BPS) Skyrme model, allows both for an exact field-theoretic and a mean-field treatment of neutron stars, as a consequence of its perfect fluid property. A pure BPS Skyrme model description of neutron stars, however, only describes the neutron star core, by construction. Here we consider different possibilities to extrapolate a BPS Skyrme neutron star at high baryon density to a description valid at lower densities. In the exact field-theoretic case, a simple effective description of the neutron star crust can be used, because the exact BPS Skyrme neutron star solutions formally extend to sufficiently low densities. In the mean-field case, on the other hand, the BPS Skyrme neutron star solutions always remain above the nuclear saturation density and, therefore, must be joined to a different nuclear physics equation of state already for the outer core. We study the resulting neutron stars in both cases, facilitating an even more complete comparison between Skyrmionic neutron stars and neutron stars obtained from other approaches, as well as with observations.